Prediction of protected band edge states and dielectric tunable quasiparticle and excitonic properties of monolayer MoSi_(2)N_(4)  

作　　者：Yabei Wu Zhao Tang Weiyi Xia Weiwei Gao Fanhao Jia Yubo Zhang Wenguang Zhu Wenqing Zhang Peihong Zhang 

机构地区：[1]Department of Materials Science and Engineering and Shenzhen Institute for Quantum Science&engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China [2]Guangdong Provincial Key Lab for Computational Science and Materials Design,and Shenzhen Municipal Key Lab for Advanced Quantum Materials and Devices,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China [3]ICQD,Hefei National Laboratory for Physical Science at the Microscale,Key Laboratory of Strongly-Coupled Quantum Matter Physics,Chinese Academy of Sciences,Department of Physics,and Synergetic Innovation Center of Quantum Information and Quantum Physics,University of Science and Technology of China,Hefei,Anhui,230026,China [4]Department of Physics,University at Buffalo,State University of New York,Buffalo,NY,14260,USA [5]Department of Physics,Dalian University of Technology,Dalian,Liaoning,116024,China [6]International Centre for Quantum and Molecular Structures,Materials Genome Institute,Department of Physics,Shanghai University,99 Shangda Road,Shanghai,200444,China

出　　处：《npj Computational Materials》2022年第1期1216-1222,共7页计算材料学（英文）

基　　金：This work is supported in part by the National Natural Science Foundation of China(Nos.51632005,51572167,11929401,and 12104207);the National Key Research and Development Program of China(No.2017YFB0701600);Guangdong Innovative and Entrepreneurial Research Team Program(Grant No.2019ZT08C044);Shenzhen Science and Technology Program(KQTD20190929173815000);Work at UB is supported by the US National Science Foundation under Grant No.DMREF-1626967;W.Z.also acknowledges the support from the Guangdong Innovation Research Team Project(Grant No.2017ZT07C062);the Shenzhen Pengcheng-Scholarship Program.W.G.acknowledges the supports by the Fundamental Research Funds for the Central Universities,grant DUT21RC(3)033.

摘　　要：The electronic structure of two-dimensional(2D)materials are inherently prone to environmental perturbations,which may pose significant challenges to their applications in electronic or optoelectronic devices.A 2D material couples with its environment through two mechanisms:local chemical coupling and nonlocal dielectric screening effects.The local chemical coupling is often difficult to predict or control experimentally.Nonlocal dielectric screening,on the other hand,can be tuned by choosing the substrates or layer thickness in a controllable manner.Therefore,a compelling 2D electronic material should offer band edge states that are robust against local chemical coupling effects.Here it is demonstrated that the recently synthesized MoSi_(2)N_(4)is an ideal 2D semiconductor with robust band edge states protected from capricious environmental chemical coupling effects.Detailed many-body perturbation theory calculations are carried out to illustrate how the band edge states of MoSi_(2)N_(4)are shielded from the direct chemical coupling effects,but its quasiparticle and excitonic properties can be modulated through the nonlocal dielectric screening effects.This unique property,together with the moderate band gap and the thermodynamic and mechanical stability of this material,paves the way for a range of applications of MoSi_(2)N_(4)in areas including energy,2D electronics,and optoelectronics.

关 键 词：DIELECTRIC protected QUASI 

分 类 号：O17[理学—数学]